2020-06-07T11:29:31Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1885912019-09-27T10:49:07Zcom_10261_39226com_10261_8col_10261_39228Álvaro-Blasco, José JavierEsteve, JorgeGracia, F.Zamora, Samuel2019-08-20T10:32:07Z2019-08-20T10:32:07Z2016-12-1460th Annual Meeting of the Palaeontological Association (2016)http://hdl.handle.net/10261/188591A new fossil assemblage of Cambrian Epoch 2 (early Cambrian) redlichiid trilobites has
been found in the Huérmeda Formation of the Iberian Chains, northeast Spain. This
assemblage is dominated by complete specimens characterised by macropleura-bearing
thoraxes close to the genera Onaraspis Öpik, 1968 and Myopsolenites Geyer and Landing,
2004, the former reported from Australia and the latter from the Mediterranean and
Polish margins of Gondwana. Despite their cephalic similarities, these taxa display highly
diversified thoraxes and shield-like pygidia. Although the number of segments in the
trunk and the proportions allocated to the thorax and pygidium varied with ontogeny,
several Iberian genera and species can be taxonomically differentiated based on trunk
features. Cambrian diversification not only featured evolutionary ‘experiments’ with the
constructional framework for the trilobite cephalon, but also for the trilobite trunk. The
Cambrian diversification in the development of the trunk represents a wakeup call for
taxonomic analyses exclusively based on disarticulated cranidia, and highly controlled by
taphonomic biases.engclosedAccessOne head with two bodies the Onaraspis-Myopsolenites trilobite conundrumcomunicación de congreso